a bit lost - how to truly reflect colour in Vray/3DS?

Hi all

Im having a few issues and i need some help on how some of you pros out there tackle this.

A lot of my clients choose their exterior and interior colours from this atlas (based in Australia):

http://www.dulux.com.au/applicator/colour/colour-atlas

It can either be for stucco/corrugated iron roofing/interior walls etc.

When i download the colour from their swatches on the site mentioned above, the colour almost never looks the same. It looks quiet different when rendered. I do realise that the below factors affects the colour:

Camera white balance

reflection amounts

type of environment used (ie sun conditions, whether it be afternoon sun or midday sun)

.... you get the idea.

So when i am applying these colours downloaded from the site above, i simply put it in the diffuse and adjust the material depending on whether its metal/plaster/stucco etc etc....

As i mentioned, it almost never looks the same and I find it challenging to ensure I am replicating the colour in real world space.

Hope this makes sense.

Please help if you can.

You need to correct for the Gamma space you are working in. There are a few ways to do this, the easiest IMO is to:

1. Screenshot with all the colors you want to use (hopefully this site lets you do that)
   
2. Save this image for reference throughout project
   
3. Open the image with Rendering>View Image File Make sure to apply your gamma to the image (this may take some testing)
   
4. Select color in your Material Editor and use Eye Dropper to select the color you want
   

Hopefully that helps. There is another way I have not used but saw posted somewhere the other day that involves doing math to manually convert the RGB to the 2.2 curve.

The math is: 255*((n/255)^2.2) where n equals the value given in the the eyedropper of a program such as Photoshop.

http://www.workshop.mintviz.com/tutorials/colour-correct-rgb-values-within-autodesk-3ds-max/

I used it recently and it is quite effective.

Why is manually assigning the curve is better then sRGB button in VFB?

Why is manually assigning the curve is better then sRGB button in VFB?

This is a different issue. The issue is that if you have a exact color that you want to put on something and you put in the uncorrected RGB value it will be washed out vs. what you wanted. That math is compensating for the fact that your image with have the 2.2 curve applied. You can see it in the Material Editor. Do one of each and put it next to the color you are trying to replicate.

Its the same as loading in a bitmap at 1.0 vs 2.2. One is what you were intending and the other makes the bitmap washed out or super contrasty.

Here is an example. The left material was created with the numbers photoshop gave me with the eyedropper. On the right material I did the math and adjusted it. Notice that the left one looks nothing like the color I was trying to get, the right one is dead on.

Hope that clarifies.

Yes indeed, I will give it a try in the next project.

I originally did not understand the thread so I meant to ask what is the difference between sRGB button in VFB and applying gamma correction via curves..

thanks for the response guys - ill do some testing on what youve suggested and report back soon.

much appreciated.